Written and collected by Zia H Shah MD, Chief Editor of the Muslim Times

Introduction:

The belief in one God – as professed in Judaism, Christianity, and Islam – can be supported by a cumulative argument that spans philosophical reasoning, historical development, and scriptural testimony. First, classical philosophical arguments suggest the existence of a necessary, ultimate being consistent with the attributes of the God of Abraham. Next, the historical record shows the emergence and enduring influence of monotheism through the figure of Abraham and his spiritual legacy. Finally, the sacred scriptures of the Torah, Bible, and Quran consistently describe a divine being with the same core nature and attributes. Together, these perspectives build a logical progression from general theism to the specific one God of the Abrahamic faiths.

1. Philosophical Foundations for a Single Ultimate Being

Philosophers and theologians have long proposed various arguments for the existence of God. Four classic arguments – Cosmological, Teleological, Moral, and Ontological – each offer a different angle of reasoning, and together they form a robust theistic framework pointing toward a singular, all-powerful divine being:

• Cosmological Argument (First Cause/Contingency): This argument begins from the existence of the universe and contingent things (things that need not exist). It posits that contingent beings cannot exist on their own and require an ultimate cause or explanation. Tracing the chain of causation or explanation back, one must arrive at a necessary being that itself has no cause and must exist by its own nature​plato.stanford.edu. In other words, because there is something rather than nothing, there must be an uncaused cause or a self-existent foundation of all reality – a being whose non-existence is impossible and who explains the existence of everything else​en.wikipedia.org. This necessary being is identified as God, the creator and sustainer of the contingent universe.
• Teleological Argument (Design and Purpose): This argument observes order and purpose in the natural world and infers an intelligent designer. The complexity of life and the laws of physics appear finely tuned and goal-directed rather than random. As classical philosopher Thomas Aquinas put it, even non-intelligent things in nature act toward beneficial ends, which implies they are directed by some knowledge or intelligence – “therefore, some intelligent being exists by whom all natural things are directed to their end; and this being we call God”​en.wikipedia.org. Similarly, Sir Isaac Newton, reflecting on the elegant mechanics of the solar system, wrote that such an order “could not have arisen without the design and dominion of an intelligent and powerful being”​en.wikipedia.org. The teleological argument thus suggests a wise Creator who planned the universe with purpose.
• Moral Argument (Objective Morality): This line of reasoning starts from the reality of moral values and duties. If there are objective moral truths (certain things that are truly right or wrong regardless of human opinion), there must be a transcendent source of morality. Mere societal convention or evolution cannot fully account for an absolute moral law. The argument, as articulated by thinkers like Immanuel Kant and William Sorley, is that objective moral law implies a moral Lawgiver. In fact, even some skeptics concede that if moral truths are real and binding, they “would warrant a supernatural explanation”​en.wikipedia.org. One formulation is: (1) If morality is objective and absolute, God must exist (as the source of that moral order); (2) Morality is objective and absolute; (3) Therefore, God exists​en.wikipedia.org. The God arrived at through this argument is a perfectly good being who grounds the moral law – a being concerned with justice and the goodness of creation.
• Ontological Argument (Perfect Being): The ontological argument is more abstract, proceeding from the idea of God to the existence of God. First developed by St. Anselm, it defines God as “that than which nothing greater can be conceived.” If such a maximally great being exists even as an idea, we can conceive that it would be greater for this being to exist in reality rather than merely in the mind. To imagine the greatest possible being as not existing would be a contradiction – for it would mean we could conceive of something greater (the same being with real existence)​iep.utm.edu. Therefore, the very concept of the greatest conceivable being entails its existence in reality​iep.utm.edu. In plainer terms, a God who exists is greater than a God who is merely imaginary, so the truly greatest possible being must exist. This argument points to God as a necessary, self-existent reality whose existence is inferred from the idea of supreme perfection.

Synthesis of Philosophical Arguments: Each of these arguments approaches the question of God from a different angle (causation, design, morality, and logic), yet they remarkably converge on a similar description of deity. The being indicated by these lines of reasoning would be an uncaused, necessary reality behind all existence (from the cosmological argument) who is enormously intelligent and purposeful (from the teleological argument), morally perfect (from the moral argument), and maximal in greatness (from the ontological argument). Such a being would, by definition, have attributes classically ascribed to “God”: necessary existence, omnipotence, omniscience, and moral perfection. Indeed, if a necessary being is the ultimate cause of all else, it would effectively have power over all contingent reality and knowledge of it, implying it is all-powerful and all-knowing​ plato.stanford.edu. The concept of a most perfect being likewise entails having every great-making property (such as power and knowledge) to the maximal degree. Furthermore, the unity of this being follows from its omnipotence: there cannot logically be two absolutely omnipotent, independent powers, since an all-powerful being would have no equal (any “other god” would be subordinate or dependent)​ reasonablefaith.org. The philosophical case thus leads us to a single, ultimate Creator who is unlimited in knowledge and power, exists by necessity, and is perfectly good – a description fitting the God worshipped in Abrahamic monotheism.

2. Historical Trajectory of Monotheism and Abraham’s Legacy

The idea of one God is not only a philosophical conclusion but also a historical development associated with the Near East. In particular, Abraham stands as a seminal figure in the history of monotheism. According to tradition, Abraham lived around the early 2nd millennium BCE and is revered as the first patriarch to affirm faith in one God. He rejected the idolatries of his time and entered into a covenant with a single deity. As a result, “Abraham was the first of the Hebrew patriarchs and a figure revered by the three great monotheistic religions—Judaism, Christianity, and Islam.”​ britannica.com. Each of these faiths looks back to Abraham as a champion of the belief that there is only one true God.

From Abraham’s time forward, the concept of one God took root and gradually spread. His descendants formed the people of Israel, among whom strict monotheism eventually flourished. Historically, Judaism became “based on a strict, exclusive monotheism,” centered on the sole worship of Yahweh, the God of Israel​ en.wikipedia.org. In an ancient world rife with polytheistic cultures, the Israelites (especially by the time of their prophets) increasingly emphasized that Yahweh alone is God and there is no other. This was a revolutionary emergence of ethical monotheism, setting the stage for a profound shift in religious thought.

Centuries later, Christianity inherited this Jewish monotheistic framework and identified the God of Israel as the father of Jesus Christ. Early Christians, while developing new theological insights (such as the concept of the Trinity), upheld the core principle that there is only one God – the creator of heaven and earth – who had revealed Himself in the history of Israel​ paulsarmstrong.com. Through the spread of Christianity in the Greco-Roman world, the Abrahamic idea of one supreme God became entrenched across Europe and beyond, dramatically impacting Western civilization’s philosophy, law, and ethics.

In the 7th century CE, Islam arose in Arabia and explicitly reasserted the Abrahamic doctrine of monotheism. The Prophet Muhammad, positioning his message as a return to the faith of Abraham (Ibrāhīm), forcefully proclaimed that there is no deity but the One God. Islam regards Jews and Christians as “People of the Book” who had received earlier revelations of the same God, and it seeks to correct deviations by restoring pure monotheism (tawḥīd). As a result, all three religions – though developing in different eras and cultural contexts – share “a common foundation in worshipping Abraham’s God”, known as Yahweh in Hebrew and Allah in Arabic​ en.wikipedia.org. The continuity of this God-concept across different periods is remarkable: from ancient Israel to the modern world, the God of Abraham has been continuously worshipped, albeit with variations in understanding and practice.

Impact on World History: The monotheistic idea introduced by Abraham and carried forward by his spiritual heirs has had an unparalleled impact on world history. It gave rise to value systems that emphasize a universal moral order under one supreme deity, in contrast to the localized and often morally ambivalent gods of pagan antiquity. The spread of the Abrahamic faiths eventually influenced billions of people and numerous civilizations. Monotheism became a driving force behind movements for social reform and conceptions of human dignity (for instance, the idea that all humans are equal before the one God). It also laid an intellectual foundation for the rise of science in medieval Europe, as some scholars argue that seeing nature as the rational creation of one law-giving God encouraged the search for unified natural laws​ wisdomlib.org​ wisdomlib.org. In short, the belief in one God – the God of Abraham – has proven to be a powerful and enduring idea, reshaping the religious landscape of humanity and providing a shared reference point for Jewish, Christian, and Islamic civilizations through the ages.

3. Scriptural Convergence on God’s Nature and Attributes

Finally, the scriptures of the Abrahamic religions themselves attest to a strikingly similar understanding of God. Despite being written in different languages, eras, and cultural contexts, the Hebrew Bible, the Christian New Testament, and the Quran all describe a deity with the same essential identity and attributes. This scriptural harmony reinforces that the God established by philosophical reasoning and encountered in history is indeed the one God revealed in these faiths.

Divine Unity: All three scriptures emphatically declare that there is only one God. In the Hebrew Torah, this belief is encapsulated in the Shema, an ancient prayer from Deuteronomy: “Hear, O Israel: The LORD is our God, the LORD is One”​ en.wikipedia.org. This verse (Deut. 6:4) is the cornerstone of Jewish theology, affirming both God’s oneness and Israel’s exclusive devotion to Him. Centuries later, Jesus in the New Testament reaffirms the very same commandment as the most important of all: “Hear, O Israel: The Lord our God, the Lord is one.” (Mark 12:29)​ paulsarmstrong.com.

The early Christians, though they worshiped Jesus as divine, maintained that they were not introducing a new god but rather understanding Jesus as one with the God of Israel – thus preserving monotheism (a nuanced theological development beyond this scope). Similarly, the Quran repeatedly stresses God’s oneness in the strongest terms. One illustrative passage is Surah al-Ikhlās, a short chapter often seen as a succinct summary of Islamic monotheism: “Say: He is Allah, [who is] One, Allah, the Eternal Refuge. He neither begets nor is born, nor is there to Him any equivalent.”​ en.wikipedia.org.

In another verse, addressed to all people, the Quran declares: “Your God is One God: there is no god but Him, the Most Merciful, the Most Compassionate.” (Quran 2:163)​ paulsarmstrong.com. Across all these scriptures, the message is unambiguous – there is only one true God, and any others are false. The unity of God is thus a unifying doctrine of Judaism, Christianity, and Islam, despite their other theological differences.

Divine Attributes: Not only do the scriptures agree on God’s singularity, they also ascribe to God a consistent set of supreme attributes. Throughout the Torah and later Jewish writings, God is portrayed as the Almighty Creator of the universe (Genesis 1:1) who is all-powerful, all-knowing, and utterly holy. For example, Jeremiah 32:17 exclaims, “Ah Lord GOD! You have made the heavens and the earth by your great power… nothing is too hard for you,” affirming omnipotence; and Psalm 147:5 declares, “Great is our Lord, and abundant in power; His understanding is beyond measure,” affirming omniscience. The Hebrew prophets depict God saying, “I am God, and there is none like me, declaring the end from the beginning” (Isaiah 46:9-10), emphasizing unmatched knowledge and sovereignty. In the New Testament, these attributes are echoed: “With God all things are possible” (Mark 10:27) speaks to omnipotence, and “God… knows all things” (1 John 3:20) speaks to omniscience. The New Testament also highlights God’s omnibenevolence (perfect goodness and love), for instance “God is love” (1 John 4:8), which, while especially emphasized in Christian theology, is compatible with the portrayal of God’s mercy in Judaism and Islam. The Quran concordantly attributes every perfection to Allah. He is called Almighty (Al-Aziz) and All-Knowing (Al-‘Alim) repeatedly in the Quran, and is described as merciful and just. One passage proclaims: “No vision can grasp Him, but His grasp is over all vision; He is above all comprehension, yet is acquainted with all things.” (Quran 6:103) – highlighting transcendence and omniscience. According to Islamic teaching, “the Most Excellent Names belong to God” (Quran 7:180), traditionally enumerated as 99 Names of Allah, which include attributes like the All-Powerful, All-Wise, Ever-Living, and Eternal. In summary, all three traditions conceive of God as eternal, omnipotent, omniscient, and morally perfect – in short, the greatest possible being. In the words of one summary of Abrahamic belief: “In the Abrahamic tradition, God is one, eternal, omnipotent, omniscient, and the creator of the universe”​ en.wikipedia.org, holy and just, yet also compassionate and personally concerned with humanity. This alignment is remarkable given the independent development of the scriptures; the God worshipped by Moses, by Jesus and the apostles, and by Muhammad is recognizably the same in fundamental character.

Consistent Identity: Beyond abstract attributes, the identity of God carries over from one scripture to the next. The God who spoke to Abraham and Moses identifies Himself as the same God addressed by later prophets and by Jesus and Muhammad. For instance, when God calls Moses, He says “I am the God of your father, the God of Abraham” (Exodus 3:6), tying His identity to the covenant with Abraham – an identity which Christians also embrace, calling upon “the God of Abraham, Isaac, and Jacob” (Acts 3:13) in the New Testament. The Quran directly links its God with the God of previous revelations, saying “We believe in the revelation which has come down to us and in that which came down to you; our God and your God is One, and to Him we submit” (Quran 29:46). Each faith thus insists it is not worshipping a new or different deity, but the very same One God who made the world and guided Abraham. The continuity of God’s identity and attributes in the Torah, Bible, and Quran bolsters the claim that they refer to the same reality – the unique Creator who alone is worthy of worship.

Conclusion: By examining the question of God’s existence and identity from these three vantage points, we see a convergence of evidence. Philosophically, reason points to a necessary, supreme being with the characteristics of the God described by classical monotheism. Historically, the emergence of monotheism and its preservation through Abraham’s lineage show a clear thread of belief in one God influencing diverse peoples and eras. Scripturally, the holy texts of Judaism, Christianity, and Islam – despite doctrinal differences – consistently proclaim a single, sovereign God who possesses incomparable attributes. This unified picture provides a cumulative case that the God of the philosophers and the God of Abraham are one and the same. In other words, the general concept of a Creator arrived at through cosmological and moral reasoning finds specific embodiment in the God worshipped in the Abrahamic faiths en.wikipedia.org. The harmony of logical argument, historical record, and scriptural witness offers a compelling argument for the existence of the God of Abraham – one God, almighty and all-good, who made heaven and earth and who continues to be the ultimate ground of reality and source of moral truth in the worldview of billions of people. Such a cumulative argument does not “prove” God in the manner of a mathematical proof, but it does show that belief in the God of Judaism, Christianity, and Islam can rest on a coherent and broad foundation of support, resonating with both our reason and our deepest historical and spiritual intuitions.